Respostas

2014-01-12T15:50:59-02:00
f(x)=x²-9x+8
x²-9x+8=0
a= 1 b= -9 c-8
Δ= b²-4ac
Δ= (-9)²-4·1·8
Δ=81-32
Δ=49

x= -b+/-√Δ/2a
x= - (-9) +/-√49/2·1
x= 9+/-7/2

x'= 8
x''= 1

S:[1,8]
1 5 1
2014-01-12T16:58:14-02:00
F(x)= 1x²-9x+8
\boxed{A = 1 , B = -9 , C = 8}

Δ = b² -4ac
Δ = (-9) ² -4.1.8
Δ = 81 - 32
Δ = 49

x = -b 
 ± √Δ
          2a

x = -(-9)  ± √49
            2.1

x =  ± 7
         2

\boxed{x' =\frac{9+7}{2} =  \frac{16}{2} = 8}

\boxed{x''= \frac{9-7}{2} =  \frac{2}{2} = 1}
1 5 1